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Post by toneloc on Sept 5, 2012 10:55:11 GMT -5
Absolutely. If you can bias Class A to 40-60 watts and implement effective heat management, then it's a great idea.
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Post by zaphod2012 on Sept 5, 2012 11:00:49 GMT -5
Lonnie,
i personally am intregued with this option, much depends on cost and benefit. If it costs too much and does not provide the desired improvment then we won't buy it and you will not sell it, neither desireable. Again my concer is in reality howe much class A will be available under NORMAL usage. Lets say i have 2-7 of them, if they are stacked and are kept on standby as a minimum every day, which is what i do now, then will they actually work at 30 watts class A or 60 watts class A if you double it. Also what would you expect the costs to be? If a XPA_1L is 549-699, I have seen both, and the XPA-100 is 449, the XPA_1 is 999, then we could expect this XPA-1LA+ to be somewhere around 1099-1299, now how would it compare to a XPR-2, cost and sound?
but you certainly have got some interest with this
Paul
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DYohn
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Post by DYohn on Sept 5, 2012 11:12:40 GMT -5
Now I have a question for you guys. Do you think I should make a new version of the big XPA-1 and add the Auto Class A-A/B circuits?  Lonnie Yes. And you should make the amp have an inner glow, like a giant tube. Oh wait, it might anyway... |
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bootman
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Post by bootman on Sept 5, 2012 11:18:35 GMT -5
I would like to see the XPA-2 do this also into 2ch.
..along with more affordable "green" amps using different topologies especially for multi channel applications.
As the audiophile in me drools in a all class A 7ch setup, the realist in me would rather have an all class H/D etc amp doing HT duties.
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Post by haugesund on Sept 5, 2012 11:27:09 GMT -5
You're right Jim. I had understood it to be switchable from A A/B to A/B via a physical switch but I don't see the switch for that so maybe I'm mistaken. It must just auto switch depending on heat and output demands. The amplifier will switch from Class A to Class A/B under a few set conditions. First is when the heat sink temperature rises above a set point the system will start to reduce the class A drive gradually and continue to reduce the class A (as the heat sink temperature rises) until it either reaches a point of stasis or the temperature on the heat sink rises to a second set point in which case the amp will just run into class A/B mode until it cools down. The second is when the input signal is greater than the 30 watts of Class A, then it will just move into class A/B for the higher power output. The last scenario is if you want it to just run in Class A/B mode. There is a switch on the back panel that in one position is Auto Class A-A/B and the other position is Class A/B only. The sample that was on display did not have this switch as it was decided to add it later. Now I have a question for you guys. Do you think I should make a new version of the big XPA-1 and add the Auto Class A-A/B circuits? Lonnie Absolutely |
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Post by garbulky on Sept 5, 2012 11:42:32 GMT -5
You're right Jim. I had understood it to be switchable from A A/B to A/B via a physical switch but I don't see the switch for that so maybe I'm mistaken. It must just auto switch depending on heat and output demands. The amplifier will switch from Class A to Class A/B under a few set conditions. First is when the heat sink temperature rises above a set point the system will start to reduce the class A drive gradually and continue to reduce the class A (as the heat sink temperature rises) until it either reaches a point of stasis or the temperature on the heat sink rises to a second set point in which case the amp will just run into class A/B mode until it cools down. The second is when the input signal is greater than the 30 watts of Class A, then it will just move into class A/B for the higher power output. The last scenario is if you want it to just run in Class A/B mode. There is a switch on the back panel that in one position is Auto Class A-A/B and the other position is Class A/B only. The sample that was on display did not have this switch as it was decided to add it later. Now I have a question for you guys. Do you think I should make a new version of the big XPA-1 and add the Auto Class A-A/B circuits? Lonnie Lonnie did you even have to ask?! YES!  Heck you could even add a third switch that limited it to pure class A all the way and then only switch to AB for temperature reasons nothing else. I can only imagine how much class A watts that would take! |
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Post by Dark Ranger on Sept 5, 2012 11:53:29 GMT -5
Photos of the rear showing the Tiffany style RCA's, locking XLR connection, metal toggle bal-unbal switch and high quality binding posts. Due to being balanced the Pos and Neg terminals are some distance apart similar to the XPA-1. 250 Watts fully balanced in a nice manageable chasis like this is truly awesome. The Class A ability is just icing on the cake. I wish I could have gave it a listen.  Thanks for the pic of the rear, briank. Everything looks really good. Love the binding posts, Tiffany style RCAs, and locking XLR connector. The distance between the binding posts is more than I expected, but it makes sense considering the rear panel layout. I hope my Emo X-Series speaker cables can split that far, otherwise I'll be needing new cables! Also, I can't tell from the pic, but it seems like the nominal power consumption is ~350 watts. I could be wrong since it's a bit blurry. As pointed out by Jim, I also noticed the lack of a physical switch for toggling between A and A/B mode. However, Lonnie cleared that up (I got worried there for a minute  ). The amplifier will switch from Class A to Class A/B under a few set conditions. First is when the heat sink temperature rises above a set point the system will start to reduce the class A drive gradually and continue to reduce the class A (as the heat sink temperature rises) until it either reaches a point of stasis or the temperature on the heat sink rises to a second set point in which case the amp will just run into class A/B mode until it cools down. The second is when the input signal is greater than the 30 watts of Class A, then it will just move into class A/B for the higher power output. The last scenario is if you want it to just run in Class A/B mode. There is a switch on the back panel that in one position is Auto Class A-A/B and the other position is Class A/B only. The sample that was on display did not have this switch as it was decided to add it later. Lonnie, thanks for the additional info and clarification. I really appreciate it. This amp is turning out to be incredible, both for potential sound quality and for flexibility. The A/A-B toggle switch is genius, not to mention the small form factor. By the way, I was kicking around the meaning of the "L" identifier yesterday. I figured it meant L(ow profile) or L(ite), but it occurred to me that since you designed it, I like to think it means L(onnie Edition).  I have a feeling this amp is gonna be a hit! I had written off monoblocks a while back for several reasons, but this amp seems to do everything right. Dan and Lonnie sure know how to keep a guy's wallet open! |
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Post by garbulky on Sept 5, 2012 11:57:03 GMT -5
Photos of the rear showing the Tiffany style RCA's, locking XLR connection, metal toggle bal-unbal switch and high quality binding posts. Due to being balanced the Pos and Neg terminals are some distance apart similar to the XPA-1. 250 Watts fully balanced in a nice manageable chasis like this is truly awesome. The Class A ability is just icing on the cake. I wish I could have gave it a listen. Thanks for the pic of the rear, briank. Everything looks really good. Love the binding posts, Tiffany style RCAs, and locking XLR connector. The distance between the binding posts is more than I expected, but it makes sense considering the rear panel layout. I hope my Emo X-Series speaker cables can split that far, otherwise I'll be needing new cables! Also, I can't tell from the pic, but it seems like the nominal power consumption is ~350 watts. I could be wrong since it's a bit blurry. As pointed out by Jim, I also noticed the lack of a physical switch for toggling between A and A/B mode. However, Lonnie cleared that up (I got worried there for a minute ). The amplifier will switch from Class A to Class A/B under a few set conditions. First is when the heat sink temperature rises above a set point the system will start to reduce the class A drive gradually and continue to reduce the class A (as the heat sink temperature rises) until it either reaches a point of stasis or the temperature on the heat sink rises to a second set point in which case the amp will just run into class A/B mode until it cools down. The second is when the input signal is greater than the 30 watts of Class A, then it will just move into class A/B for the higher power output. The last scenario is if you want it to just run in Class A/B mode. There is a switch on the back panel that in one position is Auto Class A-A/B and the other position is Class A/B only. The sample that was on display did not have this switch as it was decided to add it later. Lonnie, thanks for the additional info and clarification. I really appreciate it. This amp is turning out to be incredible, both for potential sound quality and for flexibility. The A/A-B toggle switch is genius, not to mention the small form factor. By the way, I was kicking around the meaning of the "L" identifier yesterday. I figured it meant L(ow profile) or L(ite), but it occurred to me that since you designed it, I like to think it means L(onnie Edition). I have a feeling this amp is gonna be a hit! I had written off monoblocks a while back for several reasons, but this amp seems to do everything right. Dan and Lonnie sure know how to keep a guy's wallet open! I think the back chasis says UPA-1 but I can't be sure. ;D I don't think it's the final finished chassis. |
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Post by Dark Ranger on Sept 5, 2012 12:12:01 GMT -5
I think the back chasis says UPA-1 but I can't be sure. ;D I don't think it's the final finished chassis. You might be right about that. I enlarged the image a bit trying to find a happy medium for readability. No worries, as I understand this model is not a final version. |
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Post by kellys on Sept 5, 2012 13:37:18 GMT -5
Lonnie, I love the idea of the new XPA-1L amp very much. Regarding the XPA-1, I have to say "if it ain't broke, don't fix it." that amp is in a league with few others. Truly world class. I wouldn't change a thing.
Please keep your focus on the XPA-1L so I can buy two. (okay so I may be biased)
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harri009
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Post by harri009 on Sept 5, 2012 13:57:02 GMT -5
PLEASE LONNIE GIVE US THE XPA-1XL. This would be a direct competition to the Pass Labs X600.5 $22,000 amp. I would buy your XPA-1XL today!!!!! The higher class A the better, If I can turn off my heater in the winter thats fine with me |
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harri009
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Post by harri009 on Sept 5, 2012 13:59:18 GMT -5
Also question lonnie, does the class A rating double down for 4 ohm or is it the same 30 watts in either 8 or 4? And what idle temp are we talking about with the 2 designs L and XL? thanks
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Post by wrinklemash on Sept 5, 2012 14:07:48 GMT -5
You're right Jim. I had understood it to be switchable from A A/B to A/B via a physical switch but I don't see the switch for that so maybe I'm mistaken. It must just auto switch depending on heat and output demands. The amplifier will switch from Class A to Class A/B under a few set conditions. First is when the heat sink temperature rises above a set point the system will start to reduce the class A drive gradually and continue to reduce the class A (as the heat sink temperature rises) until it either reaches a point of stasis or the temperature on the heat sink rises to a second set point in which case the amp will just run into class A/B mode until it cools down. The second is when the input signal is greater than the 30 watts of Class A, then it will just move into class A/B for the higher power output. The last scenario is if you want it to just run in Class A/B mode. There is a switch on the back panel that in one position is Auto Class A-A/B and the other position is Class A/B only. The sample that was on display did not have this switch as it was decided to add it later. Now I have a question for you guys. Do you think I should make a new version of the big XPA-1 and add the Auto Class A-A/B circuits? Lonnie Uh...YEAH! So long as it has the A-A/B and A/B only switch and doesn't increase the price too much. |
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Post by jmilton on Sept 5, 2012 14:14:37 GMT -5
Doesn't anyone care about global warming anymore?
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Post by paintedklown on Sept 5, 2012 14:27:23 GMT -5
You're right Jim. I had understood it to be switchable from A A/B to A/B via a physical switch but I don't see the switch for that so maybe I'm mistaken. It must just auto switch depending on heat and output demands. The amplifier will switch from Class A to Class A/B under a few set conditions. First is when the heat sink temperature rises above a set point the system will start to reduce the class A drive gradually and continue to reduce the class A (as the heat sink temperature rises) until it either reaches a point of stasis or the temperature on the heat sink rises to a second set point in which case the amp will just run into class A/B mode until it cools down. The second is when the input signal is greater than the 30 watts of Class A, then it will just move into class A/B for the higher power output. The last scenario is if you want it to just run in Class A/B mode. There is a switch on the back panel that in one position is Auto Class A-A/B and the other position is Class A/B only. The sample that was on display did not have this switch as it was decided to add it later. Now I have a question for you guys. Do you think I should make a new version of the big XPA-1 and add the Auto Class A-A/B circuits? Lonnie I may be the only one interested, and this may not be a cost effective thing to do...But, how about making a class A only amp? I think the biggest "buzz" for the XPA-1l has been built around those 30 class A watts. Would it be easier/cheaper to just build a 50-100W all class A differential amp, that doesn't switch to class A/B at any point? I only ask because if we weren't worried about having really powerful amps, I would think this would allow us to have a smaller, lower cost, class A source of power. Am I off base with this line of thinking?  On another note, Lonnie, I would love to see you put together an all class A tube amp. Even a 50w differential design mono-block would have me salivating all over the place. Are low cost tube amps even a viable option? |
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Post by trouble on Sept 5, 2012 18:30:56 GMT -5
Dumb Question (I'm truly ignorant about this stuff):
What causes the increase in wattage (i.e. what would make the new amp kick in to A/B)??
1. Volume?
2. Music played (Slayer vs. Lawrence Welk)?
3. Amount of continuous time the amp is used?
4. Anything else?
I have an XPA-2 for my 2-channel system and I love it. I love it enough, that at some point I'm planning on upgrading to dual XPA-1s.
My speakers will change in the near future. I'm mostly considering B&W 803 or 804s, or PSB Synchrony 1s. I currently have Monitor Audio Silver 8is.
Which version of the XPA monoblocks would make the most sense?
I typically listen to rock (Clash, Buzzcocks, Naked Raygun, Hoodoo Gurus, The Jam, REM, Oblivians, Descendents/All, Replacements, etc.), almost completely on vinyl.
My room is 13’8” x 23’10”x8, and the stereo is along the longer wall.
Any recommendations/advice?
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DYohn
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Post by DYohn on Sept 5, 2012 18:34:34 GMT -5
Dumb Question (I'm truly ignorant about this stuff): What causes the increase in wattage (i.e. what would make the new amp kick in to A/B)?? 1. Volume? 2. Music played (Slayer vs. Lawrence Welk)? 3. Amount of continuous time the amp is used? 4. Anything else? The answer is heat. The more heat you can pull out of an amplifier the more Class A power you can squeeze out of a transistor. It doesn't matter what you're putting through it: if it uses watts it creates heat. |
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Post by Poodleluvr on Sept 5, 2012 18:42:16 GMT -5
Now I have a question for you guys. Do you think I should make a new version of the big XPA-1 and add the Auto Class A-A/B circuits? Lonnie FEEDBACK: As an owner of a pair XPA-1s, I'd be interested in a a new pair of Special Edition or Anniversary Edition XPA-1s that go further than the first 10w into Class A. Also, I'm suggesting as a minimum of: the tiffany style RCA connectors, the locking XBR connectors, blue electronic VU meters, and a higher quality power-on switch-- Sweet! |
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Post by trouble on Sept 5, 2012 19:12:01 GMT -5
Dumb Question (I'm truly ignorant about this stuff): What causes the increase in wattage (i.e. what would make the new amp kick in to A/B)?? 1. Volume? 2. Music played (Slayer vs. Lawrence Welk)? 3. Amount of continuous time the amp is used? 4. Anything else? The answer is heat. The more heat you can pull out of an amplifier the more Class A power you can squeeze out of a transistor. It doesn't matter what you're putting through it: if it uses watts it creates heat. Great. So what would cause the new amp to switch from Class A? |
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Post by dean70 on Sept 5, 2012 19:24:28 GMT -5
..or a "signature" edition of the XPA-1/2 with higher quality components & Class-A power output
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